High bulk yarns

ABSTRACT

A high density bulked yarn having a bulk density of less than 0.050 g/cm3 is formed by stitching a matt comprised of bulkable synthetic continuous filaments to form a plurality of aligned seams by cutting the matt between the seams to form individual yarns and subsequently bulking the synthetic filaments locked in the seams by contacting the yarns with a heated fluid. Upon being bulked, the synthetic filaments curl to cover the seam.

United States Patent Philip J. Stevenson Durham, N.C. 785,254 Dec. 19,1968 Jan. 19, 1971 Monsanto Company St. Louis, Mo.

a corporation of Delaware [72] inventor [21 Appl. No. [22] Filed [45]Patented [73] Assignee [54] HIGH BULK YARNS 7 Claims, 4 Drawing Figs.

[52] 11.5. Cl. 112/400, 28/72.17 [51] Int. Cl B3211 7/08 [50] Field ofSearch 1 12/400;

57/143, 139, (inquired); 28/77, 72.17, (inquired) [5 6] References CitedUNITED STATES PATENTS 1,769,970 7/1930 Silve rman Jamieson et a1.

3,175,351 3/1965 Bloch 28/7Z.17X

3,330,896 7/1967 Fujita et al..... .28/72.17X

3,377,794 4/1968 Walker Z8/72.17X

3,400,531 9/1968 Ohfuka et a1. 28/7Z.17X FOREIGN PATENTS 9/1955 Germany57/143 Primary Examiner-Alfred R. Guest Attorneys-J. Bowen Ross, Jr.,Russell E. Weinkauf and John D. Upham ABSTRACT: A high density bulkedyam having a bulk density of less than 0.050 g./cm.-" is formed bystitching a matt comprised of bulkable synthetic continuous filaments toform' a plurality of aligned seams by cutting the matt between the seamsto form individual yarns and subsequently bulking the syntheticfilaments locked in the seams by contacting the yarns with a heatedfluid. Upon being bulked, the synthetic filaments curl to cover theseam.

EPATENTEUJANIQIBYI I 3.656030 I FORMING MATT OF'CO NTINUOUS BULKABLEFILAMENTS STITCHING THE MATT LONGITUDINALLY CUTTING THE MATT BETWEENROWS OF STITCHES LBULKING THE FBLAMENTS TO COVER THE STITCHES F I G. 4.INVENTOR.

PHILIP J. STEVENSON ATTORNEY area BULK YARNS BACKGROUND OFTHEINVENTION 1. Field of the Invention This invention relates to a bulkedyarn and, more particularly, to a bulked yarn which is made by theseaming of a/nonwoven batt of synthetic bulkable filaments and by thesub sequent cutting and bulking of the filaments.

2. Description of Prior Art Bulked yarns are well known in the art andare generally formed by heat treating bicomponent synthetic filaments.The primary disadvantages of yarns of this type is that the bulk densitycannot easily be controlled and the yarns are expensive to produce.Also, yarns of this type which are comprised of a plurality ofcontinuous synthetic filaments produce products having a silky ratherthat a velvetlike hand.

SUMMARY OF THE INVENTION This invention relates to the Arachne processwhich is currently used in the making of blankets and other textilefabrics where the conventional weaving and knitting steps are omitted.The Ar'a'chne process includes the forming of a matt generally fromstaple fibers and the sewing of the batt along various directions togive the matt strength. A typical product of the Arachne process isdisclosed in US. Pat. No. 3,365,918 which produces a simulated nonwovencorduroy fabric.

In the present invention, yarn strength is developed not by theconventional drafting and twisting of a fiber bundle which results in agreat loss of volume but by the stitching of a fine sewing threadthrough a fibrous matt. As a result of the superior volume to weightratio of the yarns, a savings in material of up to 20 percent can beobtained.

Therefore, an object of this invention is to provide highbulk yarns.Another object of this invention is to form highbulk yarns by sewing aseries of threaded seams in the machine direction of a continuousfilament matt and by subsequently slitting the matt between adjacentthreaded seams.

A further object of this invention is to form high-bulk yarns from mattscomprised of bulkable synthetic continuous filaments.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a matt ofbulkable synthetic filaments having a series of substantially parallelthreaded seams;

FIG. 2 is an enlarged view of a yarn having been cut from the seamedmatt of FIG. '1 prior to bulking; and

FIG. 3 is the yarn of FIG. 2 after said yarn has been subjected to abulking treatment;

FIG. 4 is a flow chart identifying the steps of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred process forforming the nonwoven web is carried out on a continuous basis as setforth in US. Pat. application Ser. No. 646,720. In that application, thefilaments having been spun and laid down onto a belt was subsequentlybonded by gaseous means; however, permanent bonding does not form a partof this invention and the matt is ultimately left unbonded. For ease ofhandling the nonwoven matt, a weak .water soluble cellulosic gum may beapplied to the matt which is subsequently removed after seaming bywashing in a hot water bath. The filaments as shown are bicomponent andmay be freshly spun from two polyamides having different heat shrinkagecharacteristics, two polyesters having differential heat shrinkagecharacteristics or a polyester and a polyamide having different heatshrinkage characteristics. Also, the bicomponent filament may be formedat a prior time and supplied to the aspirator mechanism as shown in thementioned application by means of a bobbin. Where the bicomponentfilaments are formed at a prior time, two acrylonitrile-based polymershaving different heat shrinkage characteristics may be used.

The matt which is comprised of continuous bicomponent syntheticfilaments and which has been formed on a conveyor belt is moved by theconveyor belt to a bank of sewing needles which are positioned acrossthe width of the matt. Each of the needles is adapted to sew a seamalong the length of the matt with the seams being separated from eachother a distance, the distance being determined by the ultimate denierof the produced yarn. The matt having the seams formed along the lengththereof is then fed to a slicer which is adapted to cut the mattequidistantly between adjacent seams. The yarns may then be bulked,wound onto bobbins or wound onto a beam. Where bulking is to take placeimmediately after the formation of the yarns, the yarns are contactedwith a heated gaseous medium or submerged in hot water whereupon theportions of the bicomponent fibers having the greatest heat shrinkagecharacteristics causes the filaments to bend back on themselves and tocover the threaded seam.

In reference to FIG. 1, matt 10 is comprised of a plurality ofbicomponent filaments 11 which are laid down in a manner as herein setforth. Matt 10 is provided with seams 12 which are comprised of aplurality of linearly interlocking stitches 13. As shown in FIG. 1, thepreferred orientation of filaments II is normal to the direction ofseams 12.

The density of the bulked yarns of this invention vary from 0.02 to 0.10gms/cm. In comparison, cotton yarns generally have densities of between0.45 and 1.28 gms/cm and worsted yarns have densities ranging generallybetween 0.38 and 0.73 gms/cm. Turbo-stapled acrylic fiber yarns afterbulking have densities of about 0.25 gms/cm. It can be seen thatconsiderably savings of material can be made by following the teachingsof this invention.

For some end use applications, elastic yarns find utility. The bulkedyarns of this invention are easily provided with the required elasticityby substituting threads comprised of an elastomeric urethane rubber orthe like for the mentioned threads. Such threads are generally stitchedinto the matt under tension to increase the bulk density of the yarn.

EXAMPLE I Continuous bicomponent nylon filaments, 15 denier, were spunfrom an extruder in the conventional manner. The filaments were passedthrough an aspirator jet and laid randomly onto a foaminous conveyorbelt. The weight of the matt was approximately 1.5 oz/yd The matt waspassed through a bank of sewing needles which formed a threaded seam inthe machine direction every 0.40 inch. The stitching thread was 040cotton. The stitching needles were set to sew approximately six stitchesin the matt per linear inch in the machine direction. The seamed mattwas comprised of 82 percent by weight of the bicomponent continuousnylon filaments and 18 percent by weight of the sewing thread. A seamedmatt was then passed through cutters which slit the matt equidistantlybetween each of the seams.

The density of the yarn before bulking was 0.089 gms/cm. The yarn wasthen passed through a hot water bath, the water being heated toapproximately 212 F., where bulking occurred. After bulking and drying,the density of the yarn was 0.035 gms/cm. The denier of the bulked yarnwas 5,670 and the bulked yarn had a tenacity of 4.81 lbs. and a tenacityper denier of0.38.

EXAMPLE II The procedure as set forth in example I was repeated with theexception that the matt weighed approximately 1.0 ozlyd and thebicomponent continuous nylon filaments were laid down preferentiallynormal to the machine direction. The seaming width was 0.5 in. and thematt after seaming was comprised of 83 percent by weight of thesynthetic nylon fibers, 17 percent by weight of the sewing thread. Afterslitting, the density before bulking of the yarn was 0.102 gms/cm andthe density after'bulking was 0.029 gms/cm. The bulked yarn had a denierof 5,000 a bulked yarn tenacity of 3,95 lbs. and a tenacity in grams perdenier of 0.36. It can be seen that by orienting the filaments slightlyin the direction normal to the machine direction, the density afterbulking decreases.

The specification has set forth a preferred embodiment of the inventionand, although specific terms are employed, they are used in adescriptive sense only and not for the purposes of limitation only, thescope of the invention being defined in the claims.

lclaim:

l. A high-bulked textile yarn comprising a stitching includingindividual and interconnected stitches of fine threads extendingcontinuously in a given direction and a plurality of bulked staplebicomponent synthetic fibers having been trapped by said individualstitches along a given direction with a number of sald fibers beingarranged transversely with respect to said given direction and being ofsuch lengths to be entangled and curled about said stitching tosubstantially cover the same.

2. The high-bulked textile yarn of claim 1 wherein said bicomponentsynthetic fibers are comprised of two polyamides having differentshrinkage characteristics.

3. The high-bulked textile yarn of claim 1 wherein said bicomponentsynthetic fibers are comprised of two polyesters having differentshrinkage characteristics.

4. The high-bulked textile yarn of claim 1 wherein said bicomponentsynthetic fibers are comprised of polyesters and polyamides havingdifferent shrinkage characteristics.

5. The high-bulked textile yarn of claim 1 wherein said bicomponentsynthetic fibers are comprised of two acrylonitrile-based polymershaving different shrinkage characteristics.

6. The high-bulked textile yarn of claim 1 wherein said yarn has a bulkdensity of less than 0.001 gms/cm" per cubic centimeter.

7. The high-bulked textile yarn of claim 1 wherein said stitchingconsists of an elastic yarn.

2. The high-bulked textile yarn of claim 1 wherein said bicomponentsynthetic fibers are comprised of two polyamides having differentshrinkage characteristics.
 3. The high-bulked textile yarn of claim 1wherein said bicomponent synthetic fibers are comprised of twopolyesters having different shrinkage characteristics.
 4. Thehigh-bulked textile yarn of claim 1 wherein said bicomponent syntheticfibers are comprised of polyesters and polyamides having differentshrinkage characteristics.
 5. The high-bulked textile yarn of claim 1wherein said bicomponent synthetic fibers are comprised of twoacrylonitrile-based polymers having different shrinkage characteristics.6. The high-bulked textile yarn of claim 1 wherein said yarn has a bulkdensity of less than 0.001 gms/cm3 per cubic centimeter.
 7. Thehigh-bulked textile yarn of claim 1 wherein said stitching consists ofan elastic yarn.